The invention relates to a method for producing a gas discharge display panel. A manufacturing process of this type is described in the U.S. Pat. No. 3,778,127.
The U.S. Pat. No. 3,778,127 discloses a gas discharge display whose cell is assembled as follows: Two electrode plates are stacked--separated by a spacer--and a frame is formed by glass solder rods. This stack is brought to the soldering temperature T.sub.1 at which the glass solder liquefies, and then cooled to room temperature T.sub.r. Subsequently the formed cell is evacuated and again heated to a baking temperature T.sub.a to degas its interior. The baked cell is cooled again and finally filled with its operating gas.
In order that the soldering process does not unduly strain the cell parts, the glass solder should melt at a temperature no greater than 450.degree. C. A stable glass solder with so low a melting temperature permits baking temperatures of 320.degree. C. at best. Higher T.sub.a values increase the danger that the cell will become unusable due to leaks, plate cracks and/or conductor ruptures; on the other hand increased temperatures would improve the cleaning effect. Increased baking temperatures would therefore be desirable for all type plasma panel displays with a cathodoluminescent layers, especially since display life is critically dependent on the impurities within the panel.
The difference between the soldering and the baking temperatures can be reduced by using a crystallizing glass solder, which crystallizes at T.sub.1 and thus becomes relatively heat-resistant. The possible increase in baking temperature T.sub.a, however, is relatively modest and must be achieved at the expense of an inferior sealing ability, because crystallizing glass solder remains relatively viscous during the entire soldering process (U.S. Pat. No. 4,071,287) and therefore cannot always easily seal the lead-through electrodes. These electrodes have normally been given complicated profiles with pronounced overhangs by means of underetching.